Unlawful arrest is a term used to describe the apprehension of a person by law enforcement officials without proper authority or grounds. There are several synonyms for this term, including false arrest, illegal detention, wrongful confinement, unlawful imprisonment, and unjust custody. These various synonyms highlight the fact that arbitrary arrest is a serious violation of an individual's civil rights and can occur when law enforcement officers act outside of their legal authority. Each of these terms reflects a different aspect of the harm caused by an unlawful arrest, emphasizing the unjust nature of this type of law enforcement behavior and the importance of protecting individual liberties through the legal system.